Solved: Question: Setting up a 2nd AP to improve WiFi coverage

Discussion in 'Tomato Firmware' started by haertig, May 16, 2018.

  1. haertig

    haertig Serious Server Member

    I am looking for the best setup to extend WiFi coverage to an (almost) dead area of my house.

    What I currently have is an ASUS RTN-66U as my main router that supplies both wired connections and WiFi service (it is running a Shibby release). There is a WiFi (almost) dead area in my house that this RTN-66U does not reach well. I am now adding an ASUS RTN-12 router (running Shibby as well) for better WiFi coverage of this dead area. The dead area has a physical ethernet wired connection to the RNT66U. Most devices in that dead area are ethernet connected to a switch, then back to the RTN-66U and do not use WiFi. These, of course, work fine. However, this dead area contains one WiFi printer that loses connection the the RTN-66U frequently and the occasional iPhone that wanders into the area and also loses WiFi. It is for these WiFi devices in the dead area that I want to use the RTN-12 as a secondary access point. I realize the RTN-12 is 2.4GHz only, and is not a gigabit router. But that's fine, it is fast enough for my planned uses.

    What I have done thus far is hooked the 12 (LAN port) to the 66 (LAN port) via ethernet cable. Both are configured as access points. The physical locations of the 66 and the 12 are as far apart as they can get - each one is at the extreme location on either end of the house. The 66 runs it's 2.4GHz WiFi on channel 6, the 12 runs it on channel 1. DHCP is disabled on the 12. WAN is disabled on the 12. All WiFi security settings and passwords are identical on the 12 and the 66. The 66 is the gateway for the 12, and provides DHCP. The 12 is currently using a different SSID than the 66, for testing. A quick test verifies that I can connect to WiFi from the 12 and access the internet.

    Now (finally!) my question is about the best SSID to use for the 12. Should I keep it on a different SSID as I have it now for testing, or put it on the same SSID as the 66? I believe it will work either way, but my question is what happens when a client device (a wandering iPhone) moves from an area where the 66 provides the strongest signal to an area where the 12 provides the strongest signal? Is there any kind of hand-off between the two routers so the client automatically gets the stronger signal (obviously this would require the same SSID)? It would be a waste to have the iPhone remain connected to a poor signal when it's been moved physically right next to a better choice. I am not sure if this is a feature of the client, or a feature of the server (the routers). And if it's a feature of the servers, does Tomato/Shibby provide it, or is this a higher end commercial feature that I won't have?

    As an alternate, I could centrally locate the 12 and use that as the sole access point, shutting off wireless on the 66. Actually, I would only have to shut off the 2.4 on the 66, I could leave the 5.0 on. There is yet another physical ethernet connection to the 66 in the center of the house, which is good, since I don't want a repeater scenario with its inherent decrease in bandwidth. Would this "centralized single AP" be a better setup for "wandering iPhones" than the "split setup with different channels but same SSID" I described above?

    What suggestions/recommendations would people have for me to finalize/alter the implementation of this WiFi enhancement to my house?

    Thanks in advance!
    Last edited: May 16, 2018
  2. Techie007

    Techie007 Serious Server Member

    I would recommend just how you have it now; both routers broadcasting. Go ahead and match the SSIDs. Most devices will roam seamlessly between access points. Some will do it at an interval based on signal strength, and others will do it when out of range of the one they're connected to.
  3. Monk E. Boy

    Monk E. Boy Network Guru Member

    Roaming between Access Points (APs) is a feature of clients and not a feature of APs. An AP can disassociate a client, but normally it doesn't. There is a "roaming assistant" feature in some firmwares (notably ASUS's OEM firmware) that disassociates clients below a configurable signal strength (in ASUS's case it's -70dB). I'm almost certain there's an equivalent for Tomato but I haven't actually done it so I can't say how. I think instead of signal strength it can be rigged up by client transfer rate, weaker clients can only transfer at lower rates and it boots them if they can't keep up. The problem is that what's slow for 802.11g isn't all that slow for 802.11n, and I don't think the rates have been updated for 802.11n. But, remember, I haven't done it, so this is just (possibly very ignorant) speculation.

    I normally set the SSIDs the same so you only have to configure devices once. With two or more APs you have to add all the APs to all the devices and its a pain, especially if you have to wander around to add them all.
  4. haertig

    haertig Serious Server Member

    Thanks for the replies. I think I'll just set all AP's to the same SSID.
  5. HunterZ

    HunterZ Network Guru Member

    I've been running almost the same setup for a few years now: RT-N66U as my primary WAN router + AP, and a Cat5E running under the house to an RT-N16 acting as a switch + AP. Both run Tomato.

    The RT-N16 is 2.4GHz only. Both devices have the same 2.4GHz SSID (the 5GHz is on a separate SSID).

    I can't say that I've *ever* noticed a devices actually switch from one AP to the other without me forcing a switch by toggling wifi on the client. Kind of disappointing, but better than not having coverage at all on opposite ends of the house.
  6. Monk E. Boy

    Monk E. Boy Network Guru Member

    I'm in a two bedroom apartment and I roam between APs all the time. However it is a complex from the 1930s or 1940s so the walls are very thick and I swear the closets were designed to be faraday cages. If you draw a line between you and the AP and it passes through a closet expect your signal to get cut by 75% or more. Two closets and you're at complete signal loss. And the bathroom is surrounded by closets on all sides.

    Anyway, when I travel between the living room to the back bedroom, rooms containing the two APs, I roam to the other AP because my signal drops below the -70db threshold long enough for it to disassociate me. I had a hell of a time getting a signal back there, now it's fairly neat. I did setup a process on the main AP to ping the secondary AP for 30 seconds out of every minute to stop the secondary AP from putting the ethernet connection in power saving mode. Stupid Netgear firmware.
  7. haertig

    haertig Serious Server Member

    It's quite possible (actually, "probable") that you have plaster walls that are supported by metal mesh, not the sheet rock wallboard that is typical in newer houses. We have that mesh/plaster stuff in one old rental property that we own. The walls there kill WiFi deader than a door nail.
  8. eibgrad

    eibgrad Network Guru Member

    Used to have a old place like that back in El Paso, TX. The plaster walls were literally petrified! You'd go to hang a picture and the nail would BEND rather than penetrate the wall! Fortunately this was way back in the early 2000's, before wireless really took off.
  9. Monk E. Boy

    Monk E. Boy Network Guru Member

    I grew up in a plaster house and learned how to fix a wall once after getting angry enough one day as a teenager to put my fist into one. It was a painful enough lesson that I never repeated it. Looking back I feel sorry for my mom, that was a pretty lousy repair job, but I honestly didn't know any better. (didn't go back after it set to sand it level)

    I don't think its plaster but it might be. I can get a signal from the main router in the back bedroom, just not very reliably where the tablet typically sits next to my bed. Probably because it passes through one of those blasted closets. Maybe the closet walls are all plaster. :)
  10. Sean B.

    Sean B. LI Guru Member

    Is this what you were referring to? Came across the option in wl when testing on other unrelated configurations:

    root@Storage:/opt# wl roam_trigger help
            Get or Set the roam trigger RSSI threshold:
            Get: roam_trigger [a|b]
            Set: roam_trigger <integer> [a|b|all]
            integer -   0: default
                        1: optimize bandwidth
                        2: optimize distance
                [-1, -99]: dBm trigger value
    Monk E. Boy likes this.
  11. Monk E. Boy

    Monk E. Boy Network Guru Member

    Whoa, nifty. That sounds like the feature ASUS is using. So wl roam_trigger -70 all should be equivalent to their default option. -70 might actually be too strong of a signal to roam from unless you have a lot of APs or at least some really well placed APs.
    Techie007 likes this.
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